Formation of ArF laser-induced self-assembled macrostructures on poly methyl methacrylate and CR-39 polymers

ArF excimer laser at lambda = 193 nm induces the regular macrostructures on poly methyl methacrylate (PMMA) and CR-39 with the periodicity Lambda under the proper UV doses. The periodic self-organizing pattern lucidly appears on the polymeric surface, creating the grooves parallel along with the direction of the focal line of the cylindrical lens. The spatial period Lambda is enlarged in terms of the focal length f varying tens of microns, much larger than the laser wavelength (22-145 mu m, Lambda >> lambda). The interspacing also alters in terms of the incident angle theta by the expression 1/ cos theta, however it remains nearly invariant against the laser fluence F ranging several hundreds of mJ/cm(2). Finally, the crisscross macroripples are created by situating a couple of cylindrical lenses in the orthogonal configuration. The formation of the gridiron patterns on PMMA and CR-39 attests that the linear superposition holds accordingly. (C) 2017 Laser Institute of America.